Circular arguments prove their own premises because they're circular

I meant to comment on some of the substance of Harman's interview below. Specifically, I yelled at the TV when I heard the following, loosely paraphrased, argument:

Q. Why don't you allow fathers to take more time off with a shared parental leave allowance instead of maternity/paternity leave being split.

A. We could do that, but most men would still end up working because they earn more than their partners.

Me: YES, BECAUSE THEY DON'T GO ON LONG PATERNITY LEAVE!*

In other news, the government has announced it won't be repairing the lifts in the Palace of Westminster, saying "the only people we see on the top floors are fit enough to use the stairs."

*I know it's not the only reason men tend to earn more than their partners, but it's a big factor behind a) preferential hiring and b) having more time invested in a career.